<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .test {
            height: 200px;
            background-color: plum;
        }

        .test-parent {
            margin: 0 0;
            width: 400px;
        }

    </style>
</head>
<body>
<center>
    <div class="test-parent">
        <div class="test">
        </div>

    </div>
</center>
</body>
</html>